luxaire/york 33109167000 furnace board replacement

Quote:

Originally Posted by dac122

Alternatively, if your tstat energizes G during cooling, just disconnect Y and Y1 from the furnace board and make sure the Y terminal on your tstat runs all the way out to outdoor unit. Just disconnect yellows off the furnace board and throw a wire nut on it. It would not be unusual for Unitrary products and the board manufacturer to not know how it all works. I've experinced that before.

I'm just leaving for the cottage now, but keep in mind this is a new board, which is not the same as the old board that originally came with the furnace. This new one is more universal, for multistage furnaces above my model, and it has two Y terminals, labelled "Y/Y2" and "Y1". (The old board only had one Y terminal.) On this new board, the Y1 showed no voltage, so the Y wire from the tstat was connected to the Y/Y2 terminal, which did in fact (a) show 24 volts between it and the C terminal, and (b) did energize the AC compressor (since both the tstat Y wire and the one wire from the AC unit were commonly connected to it). It was only when I moved the HV wire over from the "LO COOL" terminal to the "HI COOL" terminal (in order to get the furnace blower going) that the AC compressor stopped working. Now beenthere figures one of the LV wires is loose/broken, which I can easily check using simple continuity tests on all the wires. (But first I will check to see if I am still getting 24 volts from the various relevant terminals on the board itself.)

Thanks again, guys, for chiming in - I'm getting a lot farther with you than I am with the techies and the service people! (It's just too bad that the customer support for this company is so lousy, especially considering that my cottage is so far away from a major city. (I will never buy a York or Luxaire furnace again!)

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luxaire/york 33109167000 furnace board replacement

Surprise! I connected the HV blower wire back to the "LO COOL" terminal and sure enough, twhen the tstat called for cool the AC compressor came on but no blower (just like before). So, I now believe that, unlike the case with the old board, you cannot simply connect the black (high speed) blower wire to both the "HEAT" and "HI COOL" terminals using a jumper.

luxaire/york 33109167000 furnace board replacement

Well, the AC is now running. What I did was leave the HV black (Hi speed) blower wire connected to the HI COOL terminal, but I disconnected the (black HV wire) jumper that ran over to the HEAT terminal, and instead connected the blue HV (MED HI) wire to the HEAT terminal. Turned it on, and low and behold both the AC compressor and the blower came on.

So, CONTRARY to the instructions in the original furance installation guide (which of course pertained to the old board), you CANNOT connect both the HEAT and the HI COOL terminals to the same black (high speed) blower wire in order to get the same blower speeds for both functions. (Somehow, on the new board this disables the 24 V signal going out to the AC compressor relay.) So why the $%&#@ did it not say that on the installation instructions for the new board!? And why do these new instructions also tell you to connect a non-existant yellow blower wire to the LO COOL terminal?

Oh gee, maybe if I had just paid a furnace guy 9ABOUT $200 in travle time alone) to come out and do it, they would just know this because they are professionals! Maybe, but no one I talked to (including York/Luxaire techies) could tell me this on the phone, - the solution was so simple you would think someone would know. Not very impressive, and I am also not too optimistic about the future of this furnace, or the repair of future breakdowns, either (which WILL happen judging by the sorry reviews I have seen online for Luxaire furnaces).

Still have to recheck the heat function of course, but I'd be surprised if there is any problem.

Time to go on an ATV ride and forget about all of this.

BTW, thanks for all the help, beenthere and dac122 - it kept me going!

luxaire/york 33109167000 furnace board replacement

Furnace seems to still work OK, too - I suppose I can live with the MED HI blower speed on the heating cycle. (A bit of a concern since it gets 30 below here in the winter.) At least it will be less noisy!